Apparatus for homogenizing liquids



y' 1951 L. A. RUNTON 2,553,213

APPARATUS FOR HOMOGENJ'IZING LIQUIDS Filed Dec. 22, 1948 Patented May 15, 1951 APPARATUS FOR HOMOGENIZING LIQUIDS Leslie A. Runton, Dracut, Mass., assignor to J. P.

Stevens & Co. Inc., New York, N. Y., a corporation of Delaware Application December 22, 1948, Serial No. 66,615

8 Claims.

The object of the present invention is to provide a simple and efiicient apparatus for effecting the homogenization of liquids by the use of pressure air wave impulses of high frequency such as produced by sound generators. The apparatus disclosed is particularly useful for rendering homogeneous the aqueous viscous liquids employed as size mixtures for use in the textile art. Such liquids, for example, are employed to coat yarn with glutinous starch in order to prevent chafing of the fibres during weaving, and other textile processes, and act to secure the fibres together temporarily and after they have functioned are removed by washing or scouring. These size liquids, however, tend to break down into their components and therefore hinder their efficient, smooth and continuous operation. The present invention functions to render the size homogeneous, breaking up the particles and semi-solids, and thus preventing the undesirable separation. The apparatus, however, is not restricted to the particular liquid thus to be homogenized but may effectively be employed for a wide range of liquids where homogenization is desirable.

It is believed that the breaking up of the various particles and semi-solid elements in a liquid, as required in the process of homogenization, is due chiefly to the cavitation of the liquid, and the present invention is based upon the principle of efiecting and facilitating such cavitation. To secure this result the invention provides a bowl having a parabolical surface and rotated on its central vertical axis with the liquid to be homogenized fed through the center of the bowl and caused to flow, by the correlation of the feeding pressure and the centrifugal force due to rotation of the bowl, in a film of continuously decreasing thickness from the center over the surface and discharging over the perimeter of the bowl. And further the invention provides for continuously directing against the film of liquid flowing under these conditions pressure air wave impulses of high frequency such as produced by a sound generator. Furthermore, the apparatus in its most efficient form is provided with a parabolical reflector placed opposite the bowl and surrounding the generator so that the pressure air wave impulses generated thereby not only impact directly against the film of liquid flowing over the bowl, but are repeatedly reflected by the reflector back against the film of liquid.

The liquid flowing over the surface of the bowl is subject on its surface only to atmospheric pressure and consequently disruption of the surface where cavitation takes place may freely proceed. Furthermore, since the velocity of the fiow of the film of liquid over the bowl is rapidly increasing and the thickness of the film is constantly decreasing it follows that the speed of the particles in the liquid to be broken down, as required for homogenization, is constantly changing, thus producing a condition facilitating cavitation.

While pressure air wave impulses, such as produced by a sound generator acting under ordinary conditions against a body of liquid, are largely reflected, the present invention secures an efiicient transmission of such impulses from the air to the liquid by the repeated impact of these impulses due to the peculiar character and functioning of the apparatus, and the optimum result is secured with the use of the parabolical reflector. The impulses projected against and reflected back against the liquid move in paths having an infinite number of angular relations to the surfaces of the flowing liquid and moreover the liquid is moving with increasing speed in a thin film of constantly decreasing thickness, and thus cavitation takes place.

The generator employed for producing the pressure air wave impulses of high frequency is preferably a sound generator of standard form and a frequency within the sonic range is usually sufficient for the homogenization of such liquids as size employed in the textile art, but any suitable generator may be employed and the frequencies may extend into the ultrasonic range within the scope of the invention.

The nature and objects of the invention will appear more fully from the accompanying description and drawing and will be particularly pointed out in the claims.

The drawing illustrates a simple and preferred form of apparatus shown chiefly in central vertical cross section embodying a preferred form of the invention.

The apparatus as shown comprises a cylindrical metal tank I having near the top a pipe 2 opening into the tank through which the liquid to be homogenized is fed and near the bottom a pipe 3 opening from the tank for discharging the homogenized liquid. At the top the tank is preferably partially closed by an inwardly projecting rim 4. A bowl 5, preferably of metal, has secured thereto at its center a depending hollow cylindrical stem 6. This stem forms a central inlet at l to the bowl and is closed at its lower end. The inner surface of thebowl is parabolical, that is, it has the general shape of a parabola, and the perimeter of the bowl terminates in a reverse curve 8.

The bowl with its stem is journaled near the top of the stem on a ball bearing 9 in a strut ID extending transversely of the tank and connected to the side wall thereof. At its lower end the stem is journaled in a bearing plate H secured to the bottom of the tank and rests upon a ball bearing l2. At its lower end the stem has mounted thereon a pulley l3 driven by a belt Hi from a.

motor i5 shown connected exteriorly to the tank.

The hollow portion of the stem 6 opens through the wall near the bottom through diametrically arranged ports [6. A suitable pump 11 is mounted on the bottom of the tank and the casing [8 of this pump surrounds the stem -6. The suction inlet is of the pump opens into the tank and the discharge exit extends to and surrounds the stem opposite the ports [6 with stuffing boxes 2| mounted in the casing above and below. Consequently, when the pump is acting and the bowl rotating the liquid in the tank is pumped up through the stem 6 through the central inlet '1 into the bowl. The pressure of the pump and the speed of rotation of the bowl are correlated so that due to the slight pressure produced by the pump, and chiefly to the centrifugal action caused by the rotation of the bowl, the liquid in the tank is caused to flow in a film of decreasing thickness until it discharges over the perimeter of the bowl. It. will thus be seen that this film of liquid, .due to the contour of the bowl, is consequently increasing in velocity and decreasing in thickness and is preferably caused to dis- 7 charge over the perimeter in an extremely thin film or preferably little more than a spray.

A suitable generator of pressure air Wave impulses of high frequency such, for example, as a standard sound generator, is located above and centrally of the bowl. This is shown as having a disk-like impeller 22 with radial curved fins supported on a shaft 23 driven by a motor 24, with the air supplied to the impeller through the pipes 25, and surrounding the impeller an annulus containing the tangential pockets 26 open except at the perimeter 21.

The parabolical reflector 28 is mounted above the generating area of the generator facing and in axial alinement with the bowl and by parabolical is meant that'it has the general shape of a parabola. In the construction illustrated this reflector serves as a support for the elements of the sound generator and is secured to the rim 4 of the tank.

The operation of the apparatus will be clear from the foregoing explanation of its principles. Preferably as designed it operates upon the batch principle, that is, the outlet 3 is closed and the liquid to be homogenized is fed through the inlet pipe 2 until the tank is filled to a point beneath the bowl. But under some conditions it may be operated upon the continuous principle with the liquid fed continuously and slowly through the pipe 2 and as homogenization is secured discharged slowly and continuously through the exit 3.

The liquid is forced by the pump and by the reflected back from the reflector against the film in paths having an infinite number of angular relations to the surface of the film, while due to the increasing velocity of the flow of the film and the decreasing thickness of the film the speed of the particles to be homogenized is constantly changing. Thus cavitation is efiiciently effected and homogenization of the liquid secured.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is:

1. Liquid homogenizing apparatus comprising a bowl having a parabolical surface and a central inlet opening and mounted for rotation on its central vertical axis, means for rotating the bowl, means for feeding the liquid to be homogenized through the inlet opening during rotation of the bowl and under a pressure which in correlation with the centrifugal force due to rotation will cause the liquid to flow with increasing velocity in a film of continuously decreasing thickness from the opening over the surface and discharge over the perimeter of the bowl, and means located above and centrally of the bowl for generating pressure air wave impulses of high frequency directed against said film.

2. The apparatus defined and operating as in claim 1, together with a parabolical reflector above the generating area of said impulses, facing and in axial alinement with the bowl, acting to reflect impulses against said film.

3. Liquid homogenizing apparatus comprising a bowl having a parabolical surface and a central inlet opening and mounted for rotation on its central vertical axis, means for rotating the bowl, means for feeding the liquid to be homogenized through the inlet opening during rotation of the bowl and under a pressure which in correlation with the centrifugal force due to rotation will cause the liquid to flow with increasing velocity in a film of continuously decreasing thickness from the opening over the surface and discharge over the perimeter of the bowl, and a sound generator of high frequency located above and centrally of the bowl directed against said film.

4. The apparatus defined and operating as in claim 3, together with a parabolical reflector locatedpdirectly above the soundgenerator, facing and in axial alinement with the bowl acting to reflect the sound waves against said film.

5. Liquid homogenizing apparatus comprising a tank, a bowl having a parabolical surface and a depending central hollow stem opening into the bowl, means for journaling the stem in the tank, 'means for rotating the stem and therewith the bowl, a pump having an inlet to the tank and an outlet casing with an outlet port surrounding the stem, the stem having diametrical ports opening from the hollow portion to the surrounding outlet of the pump casing, the'said pump acting in correlation with the centrifugal force due to therota'tion of the bowl to cause the liquid to flow with increasing velocity in a film of continuously decreasing thickness from the stem opening into the bowl over the surface of the bowl and discharge over the perimeter of the bowl, and means located above and central- 1y of the bowl for generating pressure air wave iimpulses of high frequency directed against said 6- The apparatus defined and operating as in claim 5, together with a parabolical reflector above the generating area of said impulses, facing and in axial alinement with the bowl acting to reflect impulses against said film, V

7. Liquid homogenizing apparatus comprising a tank, a bowl having a parabolical surface and a depending central hollow stem opening into the bowl, means for journaling the stem in the tank, means for rotating the stem and therewith the bowl, a pump having an inlet to the tank and an outlet casing with an outlet port surrounding the stem, the stem having diametrical ports opening from the 'hollow portion to the surrounding outlet of the pump casing, the said 10 pump acting in correlation with the centrifugal force due to the rotation of the bowl to cause the liquid to flow with increasing velocity in a film of continuously decreasing thickness from the stem opening into the bowl over the surface of the bowl and discharge over the perimeter of the bowl, a sound generator of high frequency located above and centrally of the bowl directed against said film, and a parabolical reflector directly above said generator, facing and in axial alinement with the bowl acting to reflect the sound waves against said film.

8. Liquid homogenizing apparatus defined and 5 operating as in claim 1, in which the perimeter of the bowl is reversely curved.

LESLIE A. RUNTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 15 2,042,880 Cornell June 2, 1936 2,138,051 Williams Nov. 29, 1938 2,170,178 Williams Aug. 22, 1939 2,318,293 Cornell May 4, 1943 2,448,372 Horsley Aug. 31, 1948 

